scholarly journals Depigmented Allergoids Reveal New Epitopes with Capacity to Induce IgG Blocking Antibodies

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
M. Angeles López-Matas ◽  
Mayte Gallego ◽  
Víctor Iraola ◽  
Douglas Robinson ◽  
Jerónimo Carnés
Keyword(s):  
Birch Pollen ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Bet V 1 ◽  
Ige Binding ◽  
Linear Epitopes ◽  
Specific Igg ◽  
Allergen Extracts ◽  
Blocking Antibodies ◽  
Specific Igg Antibodies

Background. The synthesis of allergen-specific blocking IgGs that interact with IgE after allergen immunotherapy (SIT) has been related to clinical efficacy. The objectives were to investigate the epitope specificity of IgG-antibodies induced by depigmented-polymerized (Dpg-Pol) allergoids and unmodified allergen extracts, and examine IgE-blocking activity of induced IgG-antibodies.Methods. Rabbits were immunized with native and Dpg-Pol extracts of birch pollen, and serum samples were obtained. Recognition of linear IgG-epitopes of Bet v 1 and Bet v 2 and the capacity of these IgG-antibodies to block binding of human-IgE was determined.Results. Serum from rabbits immunized with native extracts recognised 11 linear epitopes from Bet v 1, while that from Dpg-Pol-immunized animals recognised 8. For Bet v 2, 8 epitopes were recognized by IgG from native immunized animals, and 9 from Dpg-Pol immunized one. Dpg-Pol and native immunized serum did not always recognise the same epitopes, but specific-IgG from both could block human-IgE binding sites for native extract.Conclusions. Depigmented-polymerized birch extract stimulates the synthesis of specific IgG-antibodies which recognize common but also novel epitopes compared with native extracts. IgG-antibodies induced by Dpg-Pol effectively inhibit human-IgE binding to allergens which may be part of the mechanism of action of SIT.

scholarly journals Seroprevalence of SARS-CoV-2-specific IgG antibodies in Kashmir, India, 7 months after the first reported local COVID-19 case: results of a population-based seroprevalence survey from October to November 2020

BMJ Open ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. e053791
Author(s):  
S Muhammad Salim Khan ◽  
Mariya Amin Qurieshi ◽  
Inaamul Haq ◽  
Sabhiya Majid ◽  
Javid Ahmad ◽  
...  
Keyword(s):  
Sampling Design ◽  
Final Analysis ◽  
Population Based ◽  
Secondary Outcome ◽  
Igg Antibodies ◽  
Serum Samples ◽  
History Of ◽  
Specific Igg ◽  
Index Value ◽  
Specific Igg Antibodies

ObjectivesWe designed a population-based survey in Kashmir to estimate the seroprevalence of SARS-CoV-2-specific IgG antibodies in the general population aged 18 years and above.SettingThe survey was conducted among 110 villages and urban wards across 10 districts in Kashmir from 17 October 2020 to 4 November 2020.ParticipantsIndividuals aged 18 years and above were eligible to be included in the survey. Serum samples were tested for the presence of SARS-CoV-2-specific IgG antibodies using the Abbott SARS-CoV-2 IgG assay.Primary and secondary outcome measuresWe labelled assay results equal to or above the cut-off index value of 1.4 as positive for SARS-CoV-2-specific IgG antibodies. Seroprevalence estimates were adjusted for the sampling design and assay characteristics.ResultsOut of 6397 eligible individuals enumerated, 6315 (98.7%) agreed to participate. The final analysis was done on 6230 participants. Seroprevalence adjusted for the sampling design and assay characteristics was 36.7% (95% CI 34.3% to 39.2%). Seroprevalence was higher among the older population. Among seropositive individuals, 10.2% (247/2415) reported a history of COVID-19-like symptoms. Out of 474 symptomatic individuals, 233 (49.2%) reported having been tested. We estimated an infection fatality rate of 0.034%.ConclusionsDuring the first 7 months of the COVID-19 epidemic in Kashmir Valley, approximately 37% of individuals were infected. The reported number of COVID-19 cases was only a small fraction of the estimated number of infections. A more efficient surveillance system with strengthened reporting of COVID-19 cases and deaths is warranted.

scholarly journals SARS-CoV-2 seroprevalence in healthcare workers of dedicated-COVID hospitals and non–COVID hospitals of District Srinagar, Kashmir

2020 ◽  
Author(s):  
Muhammad Salim Khan ◽  
Inaamul Haq ◽  
Mariya Amin Qurieshi ◽  
Sabhiya Majid ◽  
Arif Akbar Bhat ◽  
...  
Keyword(s):  
Healthcare Workers ◽  
High Risk Group ◽  
Infection Prevention And Control ◽  
Institutional Setting ◽  
Igg Antibodies ◽  
Rt Pcr ◽  
Serum Samples ◽  
Cross Sectional ◽  
Specific Igg ◽  
Specific Igg Antibodies

AbstractBackground and objectiveSARS-CoV-2 infection poses tremendous challenge to the healthcare system of nations across the globe. Serological testing for SARS-CoV-2 infection in healthcare workers, which form a high-risk group, helps in identifying the burden of hidden infection in an institutional setting.MethodsWe present the results of a cross-sectional serosurvey in healthcare workers from two different hospital settings based on their role in the management of SARS-CoV-2 patients in District Srinagar, Kashmir. In addition to testing for the presence of SARS-CoV-2 specific IgG, we collected information on influenza-like symptoms in the last four weeks and the status of RT-PCR testing. SARS-CoV-2 specific IgG antibodies were detected in serum samples using a sensitive and specific chemiluminescent microparticle immunoassay technology.Interpretation and ConclusionOf 2915 healthcare workers who participated in the study, we analysed data from 2905 healthcare workers. The overall prevalence of SARS-CoV-2 specific IgG antibodies was 2.5% (95% CI 2.0-3.1) in the healthcare workers of District Srinagar. Healthcare workers who had ever worked at a dedicated-COVID hospital had a substantially lower seroprevalence of 0.6% (95% CI: 0.2 - 1.9). Among healthcare workers who had tested positive for RT-PCR, seroprevalence was 27.6% (95% CI: 14.0 - 47.2).The seroprevalence of SARS-CoV-2 infection in healthcare workers of District Srinagar is low, reflecting that a high proportion of healthcare workers are still susceptible to the infection. It is crucial to lay thrust on infection prevention and control activities and standard hygiene practices by the healthcare staff to protect them from acquiring infection within the healthcare setting.

scholarly journals Examination of convalescents after West Nile fever for the specific IgM, IgG and neutralizing antibodies

2016 ◽  
Vol 21 (2) ◽  
pp. 82-86
Author(s):  
Alla R. Azaryan ◽  
A. A Kozlova ◽  
A. P Grishanova ◽  
E. I Ivashchenko ◽  
G. L Shendo ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Igg Antibodies ◽  
West Nile Fever ◽  
Serum Samples ◽  
West Nile ◽  
Negative Results ◽  
Igm Elisa ◽  
Control Research ◽  
Specific Igg ◽  
Specific Igg Antibodies

The examination was executed in the Astrakhan region over 2013-2014 with participation of three laboratories. In 26 convalescents after West Nile Fever (WNF) with the serological confirmed diagnosis of WNF blood sera were examined. Neurological form of WNF was observed in 8 cases, and febrile form - in 8 convalescents. Sera have been collected in 243-358 days, on average, in 308 days after the beginning of a disease. For their examination there were used IFA-IgM ELISA (MAC-ELISA), IgG ELISA methods as well as neutralization test in Vero E6 cell culture. The results of the examination in 24 of 26 patients (92, 3%) for IgM antibodies to the virus WNF were negative. In two convalescents according to the laboratories in Astrakhan and Moscow in sera there were observed low titers of IgM (1:400) with minor indices of sera optical density (0.3 to 0.4) and negative results in the Volgograd Plague Control Research Institute. Serum samples of other two convalescents were weakly positive or questionable in testing in Volgograd, but were negative when examined in the Institute of Virology. Specific IgG antibodies were detected in 23 of 26 convalescents (88.5%), neutralizing in 22 of 24 (91.7 %). These data confirm the adequacy of the criteria and tactics for WNF serodiagnosis adopted in Russia based on the application of the MAC -ELISA (IFA - IgM).

Immunity to measles in Italian children and adolescents: a persistent problem in view of measles elimination

2020 ◽  
Author(s):  
Serena Marchi ◽  
Martina Monti ◽  
Simonetta Viviani ◽  
Edmond J Remarque ◽  
Susanna Esposito ◽  
...  
Keyword(s):  
Children And Adolescents ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Susceptible Population ◽  
Persistent Problem ◽  
Measles Elimination ◽  
Measles Vaccination ◽  
Specific Igg ◽  
Italian Children ◽  
Specific Igg Antibodies

Abstract Background Despite efforts to increase coverage by two doses of measles vaccine in Italy, measles continues to circulate, with over 13 000 cases of disease since 2013. This study aimed to evaluate immunity to measles in Italian children and adolescents. Methods A total of 378 serum samples from subjects aged 9 months–18 years were collected in Northern, Central and Southern regions of Italy between 2012 and 2016. Specific IgG antibodies against measles were measured by a commercial ELISA kit. Results The frequency of IgG-positive samples ranged from 10.5% in infants under 1 year to 98.3% in children aged 6–7 years. The frequency of IgG was 72.2% in subjects aged 1–2 years, 85.6% in those aged 3–5 years and 88.3 and 86.8% in those aged 8–10 and 11–18 years, respectively. In Northern Italy, IgG prevalence was consistent with data on vaccination coverage, whereas some differences were observed in samples from subjects aged more than 8 years in Central and Southern Italy. Conclusions Our findings confirm that a large proportion of children and adolescents in Italy are still susceptible to measles. While data on first- and second-dose measles vaccination are essential, they are not sufficient to identify susceptible population cohorts to be targeted by vaccination.

scholarly journals Stable IgG-antibody levels in patients with mild SARS-CoV-2 infection

2021 ◽  
Author(s):  
Thomas Akerlund ◽  
Katherina Zakikhany ◽  
Charlotta Lofstrom ◽  
Evelina Lindmark ◽  
Henrik Kallberg ◽  
...  
Keyword(s):  
Nucleocapsid Protein ◽  
Spike Protein ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Igg Antibody ◽  
Time Period ◽  
Specific Igg ◽  
Antibody Levels ◽  
Over Time ◽  
Specific Igg Antibodies

More knowledge regarding persistence of antibody response to SARS-CoV-2 infections in the general population with mild symptoms is needed. We measured and compared levels of SARS-CoV-2 spike- and nucleocapsid-specific IgG-antibodies in serum samples from 145 laboratory-confirmed COVID-19 cases and 324 non-cases. The IgG-antibody levels against the spike protein in cases were stable over the time-period studied (14 to 256 days), while antibody levels against the nucleocapsid protein decreased over time.

scholarly journals Seroprevalence analysis of SARS-CoV-2 in pregnant women along the first pandemic outbreak and perinatal outcome

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0243029
Author(s):  
Cecilia Villalaín ◽  
Ignacio Herraiz ◽  
Joanna Luczkowiak ◽  
Alfredo Pérez-Rivilla ◽  
María Dolores Folgueira ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Horizontal Transmission ◽  
Perinatal Outcomes ◽  
Study Groups ◽  
Serological Testing ◽  
Igg Antibodies ◽  
Rt Pcr ◽  
Serum Samples ◽  
Specific Igg ◽  
Specific Igg Antibodies

Objectives To evaluate the progression of the seroprevalence of SARS-CoV-2 in the pregnant population of the south of Madrid during the first wave of the COVID-19 pandemic. Secondarily we aimed to evaluate maternal and perinatal outcomes. Study design Retrospective cohort study conducted at Hospital Universitario 12 de Octubre during weeks 10 to 19 of 2020, coinciding with the Spanish lockdown. We tested 769 serum samples obtained from routine serological testing during the first and third trimesters of pregnancy for specific IgG anti SARS-CoV-2 RBD and S proteins. RT-PCR tests were performed in suspected cases according to clinical practice. We compared maternal and perinatal outcomes in those with delivered pregnancies (n = 578) according to the presence or absence of specific IgG antibodies. Those with positive IgG were subdivided by the presence or absence of Covid-19 related symptoms at any time and the results of RT-PCR testing if performed. Therefore, we had 4 study groups: G1 (IgG negative), G2 (IgG positive, asymptomatic, RT-PCR testing negative or not done), G3 (IgG positive, symptomatic, RT-PCR testing negative or not done), and G4 (IgG positive, symptomatic, RT-PCR positive). Results Seropositivity increased from 0% to 21.4% (95% CI 11.8–31.0) during the study period, of which 27.9% had an asymptomatic course. Overall outcomes were favorable with a significant increased rate of preterm birth in G4 vs G1 (21.4% vs 6.7%) and cesarean/operative delivery (50% vs 26.9%). Asymptomatic and mild cases did not have differences regarding pregnancy course when compared to seronegative women. There were no documented cases of vertical or horizontal transmission. Conclusion Seroprevalence in pregnant women in southern Madrid went up to 21.4% of which 27.9% had an asymptomatic course. Overall perinatal results were favorable, especially in those asymptomatic.

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